I bought this aluminum Thermostat housing for my Z3, then sold the car before I got a chance to install it.
This housing replaces the plastic ones that are prone to heat damage and cracking. It is the equivalent of BMW part number 11 53 1 722 531. I think it fits a lot of different M50 and M52 engines from the early 90's on. Check the part number of yours at
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to be sure.They sell for around $30. I forget what I paid, but if someone wants to give me $15 and cover the shipping it's yours! Just send me an email to fjwills at gmail dot com.